The first No. 3 official whom Mr. Thornton drove around was Nora Slatkin, the first woman in the agency’s history to hold that position. When she interviewed him to be her driver, Mr. Thornton said, she specifically told him she didn’t like how her last driver got out of the car on the side of the road to give her privacy when she spoke on the phone.

“She said she needed to trust me,” he said. “She was busy, and she had to be where she needed to be.”

Thornton was indeed well-trusted, undergoing a security screening which included a polygraph. “You learn not to be too curious,” he told Ian Shapira of WaPo.

It's an interesting look at a man who's witnessed history from a perspective few will ever see, and includes all kinds of interesting nuggets, like the CIA having a Starbucks which requires baristas to be "highly-vetted."